Enantio- and diastereoselective transformations of cycloheptatriene to sugars and related products
摘要:
Both meso diastereomers of 6-[(tert-butyldimethylsilyl)oxy]-2-cycloheptene-1,4-diol, prepared from cycloheptatriene, have been enzymatically asymmetrized by conversion to monoacetates using Pseudomonas cepacia lipase in isopropenyl acetate. A study of protecting group manipulations, diastereoselective oxidations, and regioselective ring openings utilizing these enantiopure monacetates which results in the synthesis of all possible methyl 2,4-dideoxyhexopyranosides is described.
Enantio- and diastereoselective transformations of cycloheptatriene to sugars and related products
摘要:
Both meso diastereomers of 6-[(tert-butyldimethylsilyl)oxy]-2-cycloheptene-1,4-diol, prepared from cycloheptatriene, have been enzymatically asymmetrized by conversion to monoacetates using Pseudomonas cepacia lipase in isopropenyl acetate. A study of protecting group manipulations, diastereoselective oxidations, and regioselective ring openings utilizing these enantiopure monacetates which results in the synthesis of all possible methyl 2,4-dideoxyhexopyranosides is described.
Enantioselective Synthesis of γ-Hydroxyenones by Chiral Base-Catalyzed Kornblum DeLaMare Rearrangement
作者:Steven T. Staben、Xin Linghu、F. Dean Toste
DOI:10.1021/ja065464x
日期:2006.10.1
A cinchona-alkaloid catalyzed asymmetric Kornblum DeLaMare rearrangement has been developed. Thus, enantioenriched 4-hydroxyenones are prepared from dienes by a two-step sequence involving photochemical dioxygenation and chiral base-catalyzed desymmetrization of the resulting endoperoxides.
An Asymmetric Synthesis of <i>trans</i>-Fused Butyrolactones from Endoperoxides
作者:Joshua Priest、Mark. R. Longland、Mark R. J. Elsegood、Marc C. Kimber
DOI:10.1021/jo400177j
日期:2013.4.5
equivalents to endoperoxides in the presence of an organocatalyst yields trans-fused butyrolactones in high yield and enantioselectivities. This methodology expands the synthetic utility of endoperoxides and further underlines their potential as sources of oxygen functionality for natural and non-natural product target synthesis.